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Discussion Starter · #1 ·
Just finished rebuilding my carbs. ( Thanks to Larry's Book) Fired up right away, gave it a few minutes to warm up before adjusting the idle. Problems is that it won't go below 1800rpm. if I twist the knob back up rpms will rise, but no matter how far I twist it down they will not fall past that? Checked the choke and it has to tension on it. What am I missing?
 

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If you look at page 39 bottom left illustration you'll see that it says to push the top of the throttle cable mount plat towards the back of the carbs as you tighten it up. If the plate is too far forward when you mount it, it will hold the throttle open and cause the same situation you are describing.

Loosen the screw and push it back. You should be able to adjust the idle speed after that.

 

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Three things come to mind:



Cables installed too tight. There should be 1/8" slack at the handlebars before the mechanism moves on the carbs.



Carb bodies were separated and not properly aligned when reassembled.



Cable holding bracket on the carb has shifted. Back off the mounting screws and retighten.
 

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After cleaning mine last year, I had a fast idle that I could not adjust down. Cables were fine. What it turned out to be was a very poorly synch job. Try synching the carbs, worked for me. Mine hums now.
 

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Discussion Starter · #6 ·
I checked the cable bracket and it is fine. None of the cables had any tension on them ( i could move them easily with my finger) I did take it out for a little spin tonight of about 60 miles. When warm the idle jumps up to ~2500 rpms and falls very slowly when i take it out of gear. I put new carb boots on it as my old one on the right side had a small tear in it. The bike runs very smooth now with the exception being the idle, but even that seems alot smoother than before. For the first time I tried to find sixth gear! I did notice when I stopped for gas that the right intake may not be seated percectly, could this be causing my idle issues?
 

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I checked the cable bracket and it is fine. None of the cables had any tension on them ( i could move them easily with my finger) I did take it out for a little spin tonight of about 60 miles. When warm the idle jumps up to ~2500 rpms and falls very slowly when i take it out of gear. I put new carb boots on it as my old one on the right side had a small tear in it. The bike runs very smooth now with the exception being the idle, but even that seems alot smoother than before. For the first time I tried to find sixth gear! I did notice when I stopped for gas that the right intake may not be seated percectly, could this be causing my idle issues?
Chris,i take by your right intake,you are referring to the carb insulators.then yes,they must be perfect,with no air leak what so ever.

bike on main stand,ticking over,spray carb cleaner around all 6 carb joints.....any rise in revs,up or down,you have found your problem
 

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Discussion Starter · #8 ·
I still can't figure this one out. I readjusted all the cables, the insulators and boots are on perfect with no leaks, but it still wants to idle at 2500. Anybody have any more ideas? This is really starting to get to me!!!!
 

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Are the carb slides being stopped from moving correctly?



With the carbs off and the carbs the correct way up use your finger to lift them each in turn.They should lift and drop easily.They only have a weak spring in the top so are easilly stopped if dirty etc.
 
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